Means for bonding bolted rail joint bars



Jan. 19, 1965 H. LANSING 3,166,249

MEANS FOR BONDING BOLTED RAIL. JOINT BARS Filed Feb. 15, 1963 2 Sheets-Sheet 1 FIG. 1.

INVENTOR HORACE L. LANSING Jan. 19, 1965 H. LANSING 3,166,249

MEANS FOR BONDING BOLTEU RAIL JOINT BARS Filed Feb. 15, 1963 2 Sheets-Sheet 2 INVENTOR HORACE LANSING FIG. 3).

rolled bars of standard cross-sectional shape.

United States Patent 3,166,249 MEANS FOR BONDING BOLTED RAIL JOINT BARS Horace L. Lansing, Rutherford,NJ., assignor to Poorfiz Company, Chicago, BL, a corporation of Delaware Filed Feb. 15, 1963, Ser. No. 258,815 3 Claims. (Cl. 238-243) This application is a continuation-in-part of my prior applicationSerial No. 858,900, filed December 11, 1959, now abandoned.

This invention relates to improved means for bridging rail ends to provide bonded joints.

The practice of electrically welding the butted ends of rail-s together to provide so-called continuous rail eliminates the principal objectionable factor of maintenance incident to rail ends connected by bolted joint bars, namely the cost of labor'for track crew 'to tighten bolts of the joint, or at greater intervals etfecting bar renewals. The relative movement between the rail ends and bolted joint bars is what causes'wear on both the rail ends and the bars and consequently the bolts become loose. In addition, the elimination of the gap between the rail ends not only decreases rail end batter but also improves the maintenance of rail and tie support. Impact amounts rapidly with increased joint opening varying as the cube oi the opening. Therefore, special tamping at joints is virtually eliminated if there is no joint gap.

On the other hand, continuous welded rail also has its objections other than the initial high cost of electrically connectingthe rails and transporting them to the place where they are to be laid. Moreover, if a continuous rail cracks, breaks, or otherwise becomes damaged it is necessary to cut the rail at each side of the defective section, remove the latter, drill bolt holes in the webs of the existing laid rail ends, drill holes for replacement section and then apply a bolted joint bar of appropriate section. In addition, where continuous welded sections are used in signal track, the cumulative effect of creeping movement of a long rail length causes the insulation of bolted insulated joint rapidly to deteriorate. In continuous railsignal track, it is essential to use bolted insulated joints. For the foregoing rea sons, among others, it has been established that jointed continuous rail has practical and economic advantages over welded continuous rail.

The cost of turning up and maintaining rolls for joint bars is becoming. incredibly expensive and it is therefore desirable to use more economical press forming methods of providing joint bars;

Therefore, the practical economic answer lies in providing an adhesive bonded bolted pressed or rolled steel joint wherein the adhesive may be applied to the bars and the latter pressed into the fishing space of the rail at the time the bolts are installed and the bolts left in the final composite structure. 1

In connecting the ends of rails with bolted joint bars by an appropriate adhesive, usually of the thermo-setting type, there are two essential factors to be considered. First, it is desirable to provide a greater area of bond contact between the load bearing surfaces of the bar and the fishing surfaces of the rail thanafiorded only by the relatively narrow head and foot bearing areas of Second, since continuous adhesive bonded and bolted rail must be A repaired when broken, means must be provided to readily and conveniently break the bond between the bars and the rail ends to speedup the necessary repair. Thus, where bars are bonded by an adhesive, they may be more readily removed from the rail when the bolts are renewed thanthey could if the more expensive welding technique were followed.

Patented Jan. 19, 1965 The above-mentioned adhesive may be one of any. well known commercial adhesives on the market prior to the filing of this application. It may be any material defined as a bonding agent capable of joining many materials, including'in particular metals to maintain at least the same resistance to specific stresses in the material itself. In other words, a structural adhesive which in its final bonded. state is hard and rigid as distinguished from rubber or other pliable, compressible, orflexible material such as the more simple forms of paste and glue. By bonding withany well known and avialable structural adhesive, the joint bar and rail end-s become an integral part of the total structure. An example of such adhesive is the thermo-setting synthetic resin described in the Australian patent to Ciba Limited, No. 133,819 dated August 10, 1949; British patent to Qiba Limited, No. 630,663, dated October '18, 1949 (Class 154 Epoxy Un. Dg.) generally world-wide known as Araldite; British Plastic; November 1948, pages 521527. Also the British Patent No. 698,655, dated October 21, 1953; and US. patent to Lansing, No. 2,989,240, issued June 20, 1961; and U.S. Patent No. 3,100,080 to Fiechter, issued August 6, 1963, show a type of thermosetting adhesive to be old in the rail joint art. A useful thermosetting epoxy resin is discussed in Civil Engineering of November 1959, beginning at page 50. Thermosetting resins of the type referred to in the Australian patent are legionand Well known to the art. In fact, some two hundred and twenty-five structural thermosetting adhesive compounds, well known in the art, are applicable to the present invention.

In view of the foregoing, one of the objects of the present invention is to provide a composite bonded bolted joint including a bonding member having a vertical profile or contour to provide an extensive bonding surface in the respect that the web in addition to the load hearing surfaces can be bonded to substantially uniformly to the entire fishing surface of the rail.

A further object of the invention is to provide an augmented bonding area and a relatively small nonbonded area, substantially in the form of a tunnel or channel in the zone of the joint bolt hole to increase the resilience of the web and into which a pry-bar may be placed to remove the bonded bars when necessary or desirable. This object of the invention is attained by providing a bonding member in the form of a splice bar or shim, which may be either rolled or pressed to conform to the pattern of the fishing space of the rail, thereby to provide an extended area of contact between the bar and the rail ends to atford maximum bonding strength over a substantial area of the rail fishing space.

It is fundamental that steel which is rolled is certainly the same chemically as a pressed joint, the only difference being in the treatment and the refinement of grain which for the same carbon content will have little effect on the physical properties. The difference would be in the sectional shape, but, in cases where the sections approach each other dimensionally, the physical properties would be substantially the same. It is therefore immaterial whethe the bars are rolledor pressed.

A still further object is to provide a splice bar of light weight, as compared with standard bars of great weight, which has specially calculated physical properties according to the particular rail section with whichit will be-used.

With the above and other objects in view 'whichwill appear as the nature of the invention is better understood,

the invention consists in the novel construction, combination and arrangement of parts, hereinafter more fully described, illustrated, and claimed.

A preferred and practical embodiment of the invention is shown in the accompanying drawings, in which:

FIG. '1 is a vertical cross-sectional view ofthe primary form of the invention, and

'pha Si Zedthat it provides:

, structure;

of the rail head.

forming joint bar'seated in the web space of the rail and having pry-bar clearance.

. FIG, 2 is a side elevation of the bar-of 'FIG.'1 illustrating the bolt holes and the'bolt which are intended to be used in addition to the bond between the rail ends and the bars. 7

FIG. 3 is an end elevation of one half of a rail section and the profile of an alternate form of rail end connector.

FIGQ4 is a view similar to FIG. 3 showing a further modified form of rail end connector. I

FIG. is a View similar'to FIG. 3 showing a still further modified form of rail connector. A joint bar of the type shown in applicants Patent No. 2,785,862, dated February 27, 1952, regardless of its crosssectional shape, is a structural member (separate and distinct fromthe rail) with heavy head and base portions iilust'rating afishing space concarrying all of the load. Onthe other hand, in the present invention, the bar is essentially a connector or guide for joining the rail ends to provide in effect a continuous rail unit. The connecting member herein disclosed supports the vertical wheel loadto a certain extent, leaving the adhesive to absorb the shearstresses longitudinally. -The side thrusts which are minimal in comparison to the vertical and longitudinal loads are absorbed by the rail web through the adhesive and through the connecting member.

Thus, with regard to the present invention, it is em- Means for ,adhesively bonding rail ends together into intimate'relationship;

'Theinner faces of the joint-bar conforming to and uniformly matching the web contour of the rail when securely bonded to the trail will produce a mechanically rigid The bonding tween the matching rail web and joint bar such that they become mutually supporting; and

The cross sectional area of the joint bar has been materially reduced so as to produce a minimum of bending resistance, yet when bondedto the rail acts fully as a means of holding and aligning the rail ends.

, Referring first to FIGURES 1 and 2, it will be seen that therail-ends R.-R have their usual bolt holes H means produces a mechanical linkage besurfaces of the rail.

end connector 13 is made of thinner cross-section than the bar of FIG. 1 and has i-ts face snugly fitting the head, web, and foot portions of the bar with the exception of the medial bowed portion 8 to which is attached a metal strap 9, provided with belt holes 16, which is welded at 11 to the curved outer face of the portion 8v which stands free of the web of the rail in the zone of the bolt holes. The strap 9 is 'co-extensive with the length of the connector B and the latter is bonded to the rail surfaces with a suitable adhesive, preferably of the epoxy resin type. It will also be understood that the outer end portions of the upper and lower flanges of the connector B are initially spaced at greater distance from each other than they will be when Y bolt pressure is applied to the strap 9?, In this way, the

adhesive is firmly trapped'and pressed between the entire inner face of the connector. B and the related contacting The connector B is resilient or springy so that continuing bolt pres-sure on-the strap will maintain a mating fit with the corresponding fishing surfaces of the rail.

FIGURE 4- of the drawings shows a joint bar or rail connector B? having all of the characteristics of the connector E of FIG. 3 except that there is no outwardly The primary form of rolled or pressedsteel joint bars includes a head portion 1 with its inner compound arcuate bonding face in substantial contact with the head fishing of the rail from the point 1* under the head to and including the point 1? adjacent the zone of the bolt holes;

The foot portion 2 in a somewhat similar fashion has a bonding face conforming to the upper side of the base flange, the base fillet, and the web substantially from the point it to the point 2*.

As will be seen from FIG. 1, the bar B is formed to be initially of greater height at the outeredges of its flanges thantherelated fishing portions of the rail so that initially "the web facing contour of :the bar stands free of the rail of 1:4,which is the 'standard'inclination of the underside The. webfi is arched outwardly or bowed medially at 4- to provide anoffset bolt bearing portion and an internal channel or tunnel 5 which stands tree of the web and.

has no adhesive bond therewith. The channel 5 serves as I removed, the bars ;B may bereadily removed from the rail a point ofentry for a pry-bar so that after the bolts are a bowed portion corresponding to 8 of FIG. 3. In other words, the strap h is welded directly to the outer face of the connector at a plurality of points indicated at 11 so that the strap when subjected to bolt pressure, mates and firmly distributes such pressure uniformly to the mating inner surfaces ofthe connector and the related fishing surfaces of the rail whicnTof course are provided with bonding adhesive.

FIGURE 5 illustrates a joint bar or connector 13* of somewhat different vertical profile than that shown in FIGURE 3 and 4. As will be'seen from'the drawings, this figure illustrates a strap 9* welded to the medial portion of the connector as indicated at 11*, and while the upper flange 12 and base flange 13 are formed'to follow the related load bearing surfaces of the rail head and the base flange of the rail, nevertheless, theportion 14 at the top and bottom of the connector stands free of the rail fillets F. With this arrangement, it will-be seen that the boiting pressure wi l not only firmly bond the connector to the web of the rail, but, at'the same time, the easements provided between the inner faces of the inclined portions 14- and the rail fillets P will enable the upper flangelZ and the lower flange 13 to fully make contactwith the related surfaces of the rail. In other words, because the flanges 12 and '13 are initially spaced a greater distance apart than when they are applied, the surfaces 14will not prevent the flanges 12 and 13 to be continuing pressurized bonding contact because they are not inhibited or limited by, direct engagement with the rail fillet. i V 7 When the bonding faces of the joint bar, matching and conforming to the related head, web and base fishing areas of the rail, are connected by an adhesive 6 to the rail, and the bars and rail ends are "securely bonded in a facile, practical and inexpensive manner toprovide a continuous rail of any selected length on the site of rail laying, as distinguished from thehigh cost of welding rail ends at a mile or so away from the site of, installation with its consequent awkward transportation procedures.

the case: with joint bars which are not bonded or frozen.

This invention, therefore, provides advantages not hereto fore attainable, namely, a low cost installationj greater i flexibilityin laying of track; no maintenance for bolt tightening; convenient repair in the case ofrail breakage due to flaws in rail. rolling or resulting from a wreck;

Rail joints as shown in myprior patent are in technical terms a mechanical linkage made up of four parts and pivoting on four or six bolts. Due to the diiferences in I shape andsize the rail and joint bars will not bend equally ferential bending and achieving mechanical unity by.

the technique of adhesive bonding.

Through a rather lengthy development and test program, techniques and materials have been evolved which make it possible to bond any two given joint bars to their mating rail sections. However, in a desire to achieve the optimum design of a joint to best utilize the properties of the adhesive, the development program proceeded.

The joint bar or rail end connector is based on the following:

In the bonded joint, the motion caused by differential bending has been eliminated and in its place is a stress on the bond line which is called, for want of a better name, the bending shear stress. This stress is proportional to the free bending moment of the rail end and the free bending moment of the joint bar. The greater the difference between the two, the greater the stress.

The total shear strength of the bond line which is the load per sq. in. is the sum total of the bending shear and the shear load caused by the thermal contraction of the rail.

The shear strength of a lap joint similar to a rail joint is directly proportional to width of the bond and proportional to bond length in an increasingly smaller increment reaching a point where increased length has no further affect on strength.

If two exactly matching rail ends can be held in intimate contact, then the bending rate would be essentially that of a free piece of rail of the same length.

Thus, the problem resolves itself into providing a joint that will hold the rail ends tightly, that will have a maximum of bond width, a minimum of length, a minimum of bending stress and a minimum of bending resistance so that the entire assembly can bend as close to free rail as possible. The joint must be of suflicient section to hold the rails in alignment vertically and horizontally and also have sufficient section to withstand the total of 300,000 lbs. tensile load.

The present application provides a solution to the problem in that to achieve the rail mating, the joint is to be bonded to the rail with substantially no gap. To obtain the maximum bond area a full fishing joint is used. To overcome the inconsistencies of rail tolerance and fit, the joint is made oversized and with a sure-"it feature. It is also made as thin as possible so as to allow itself to conform to the rail fishing. A minimum of bending stress is achieved by use of the thin joint section reducing the mass and moment of inertia so that when bonded to the rail the added section will not materially affect the bending ratios of the rail. A section is welded to the back of the connector to allow places to receive bolts and also to longitudinally strengthen the section against the high tensile load requirement.

The critical portion of this proposal is the bonding of the joint bar to the rail. The reduction of cross section area to eliminate the bending resistance has left a joint section that has little or no vertical rigidity. The adhesive forms a structural link between the joint and the rail. Without this link the joint would fail. The whole principle is one of mechanical unity. The rail supplies the rigidity and bending resistance. The joint provides the alignment and the means of holding the mating ends tight enough to allow the rail to bend as a simple beam rather than as two cantilever sections.

I claim:

1. Means forming continuous bolted and adhesively bonded rail from individual rail sections, comprising, the combination with the rail sections having head, web, and base flanges defining a fishing area,

connector members of uniform vertical cross-sectional thickness throughout and including a web provided with bolt holes, the upper and lower portions of said Web conforming to the web of the rail between the head and base fillets thereof and also having upper and lower flanges of greater pitch than the under side of the rail and the upper side of the base flange of the rail, whereby the outer edges of the connector are initially disposed a greater distance apart than the related head and base surfaces of the rail fishing into which the member is applied, initially to provide an adhesive receiving pocket and to subsequently prevent said upper and lower flanges from pulling away from the related surfaces of the rail as the conforming web of the connector moves inwardly under bolt pressure to engage the related profile of the rail between said head-web and base-web fillets of the rail ends,

the medial portion of the Web offset laterally to provide a bearing for the nuts and heads of bolts, whereby, upon tightening thereof, the portions of the bar which conform to the web between said head and base fillets above and below the zone of the bolt holes are forced into substantially flush relationship with the web to trap adhesive between the flanges of greater pitch and which flanges are forced inwardly toward each other to avoid kicking out when bolt pressure is applied to said offset portion of the web and which adhesive upon hardening becomes a homogeneous structural element of the means for connecting the rail ends and causes the bar to bend uniformly with the wave motion of the rail and absorb longitudinal shear.

2. Means according to claim 1, wherein the outer surface of said medial portions of the connector members have an outwardly ofiset member bonded thereto in the zone of the bolt holes.

3. Means according to claim 1, wherein the web portion of the connector member and the upper and lower flanges are connected by an inclined portion standing free of the fillet areas of the head and foot portions of the rail.

References Cited by the Examiner UNITED STATES PATENTS 1,843,448 2/32 Faries 238-243 1,967,509 7/34 Jackson 238-243 3,100,080 8/63 Fiechter 238151 FOREIGN PATENTS 848,143 9/60 Great Britain.

ARTHUR L. LA POINT, Primary Examiner.

LEO QUACKENBUSH, Examiner. 

1. MEANS FORMING CONTINUOUS BOLTED AND ADHESIVELY BONDED RAIL FROM INDIVIDUAL RAIL SECTIONS, COMPRISING, THE COMBINATION WITH THE RAIL SECTIONS HAVING HEAD, WEB, AND BASE FLANES DEFINING A FISHING AREA, CONNECTOR MEMBERS OF UNIFORM VERTICAL CROSS-SECTIONAL THICKNESS THROUGHOUT AND INCLUDING A WEB PROVIDED WITH BOLT HOLES, THE UPPER AND LOWER PORTIONS OF SAID WEB CONFORMING TO THE WEB OF THE RAIL BETWEEN HEAD AND BASE FILLETS THEREOF AND ALSO HAVING UNDER AND LOWER FLANGES OF GREATER PITCH THAN THE UNDER SIDE OF THE RAIL AND THE UPPER SIDE OF THE BASE FLANGE OF THE RAIL, WHEREBY THE OUTER EDGES OF THE CONNECTOR ARE INITIALLY DISPOSED A GREATER DISTANCE APART THAN THE RELATED HEAD AND BASE SURFACES OF THE RAIL FISHING INTO WHICH THE MEMBER IS APPLIED, INITIALLY TO PROVIDE AN ADHESIVE RECEIVING POCKET AND TO SUBSEQUENTLY PREVENT SAID UPPER AND LOWER FLANGES FROM PULLING AWAY FROM THE RELATED SURFACES OF THE RAIL AS THE CONFORMING WEB OF THE CONNECTOR MOVES INWARDLY UNDER BOLT PRESSURE TO ENGAGE THE RELATED PROFILE OF THE RAIL BETWEEN SAID HEAD-WEB AND BASE-WEB FILLETS OF THE RAILS ENDS, THE MEDIAL PORTION OF THE WEB OFFSET LATERALLY TO PROVIDE A BEARING FOR THE NUTS AND HEADS OF BOLTS, WHEREBY, UPON TIGHTENING THEREOF, THE PORTIONS OF THE BAR WHICH CONFORM TO THE WEB BETWEEN SAID HEAD AND BASE FILLETS ABOVE AND BELOW THE ZONE OF THE BOLT HOLES ARE FORCED INTO SUBSTANTIALLY FLUSH RELATIONSHIP WITH THE WEB OF TRAP ADHESIVE BETWEEN THE FLANGES OF GREATER PITCH AND WHICH FLANGES ARE FORCED INWARDLY TOWARD EACH OTHER TO AVOID KICKING OUT WHEN BOLT PRESSURE IS APPLIED TO SAID OFFSET PORTION OF THE WEB AND WHICH ADHESIVE UPON HARDENING BECOMES A HOMOGENEOUS STRUCTURAL ELEMENT OF THE MEANS FOR CONNECTING THE RAIL ENDS AND CAUSES THE BAR TO BEND UNIFORMALY WITH THE WAVE MOTION OF THE RAIL AND ABSORB LONGITUDINAL SHEAR. 